1. Field of the Invention
The present invention relates generally to fluid handling valve guards, i.e. Class 137, subclass 382, and particularly to guards for valves located underground.
2. General Background
Water lines are located at a depth underground sufficient to prevent freezing: i.e. below the frost line. Gas lines are located underground to prevent rupture of the same. Any valve located on a fluid line underground requires access means. This is typically provided by what is simply and commonly known as a box. These boxes generally extend upward above the valve concerned to ground level and have a removable cover.
Buildings generally have a shut off valve located in what is commonly known as a curb side box, or curb box, as the same is generally located in proximity to the curb of the street on which the residential building is located. Water mains are generally located under the street and a separate line for each residential structure of a street extend perpendicularly to the water main to each residential structure. A shut off valve is located on each separate line within a curb box. Shut off valves located in curb boxes are exemplary of the structure used for valves located underground on earth buried fluid lines. Main lines are also underground but are typically either buried alongside or under a street or through a tunnel under a street where the valves are accessible by man holes. Intermediate lines connecting main lines with the separate lines for residential structures typically have valves within cases that are similar to curb boxes. Shut off valves in curb boxes are essentially the best example because these are the most plentiful underground valves within casings and the problems commonly associated with installation of curb boxes or other casings for underground valves comprise the problems addressed herein.
When a buried fluid line is installed a trench is dug, typically with a backhoe, and then filled again, again typically with a backhoe. Excavation and filling of the cavity above a valve on an underground fluid line is also typically performed with a backhoe with the curb box or other case first disposed about and above the valve. Curb boxes typically have a pair of opposed arches at the bottom for passage of the line there through without physical contact between the curb box and the line which could easily result in rupture of the line. When the cavity is filled two problems are commonly created for the valve concerned. Earth often enters the box through the arches and covers the valve. The top of the valve must be clear to permit engagement with the end, typically a socket, of a tool of sufficient length to reach the valve through the curb box from someone above ground. Secondly, the valve must be properly aligned with the curb box, i.e. pointing straight up, to easily permit engagement of the socket on the end of the tool used to operate the shut off valve.
As backhoes are typically used to fill the cavity it is also exceeding easy to knock the curb box away from the vertical orientation it must have to permit operable access to the shut off valve. This is the most common action causing both earth to enter through the arches at the bottom of the curb box in a quantity sufficient to cover the valve and to alter the alignment of the curb box with the valve. The most typical address of the first problem is to stuff rags in the arches about the fluid line. This is not considered to be very effective. After a curb box is disturbed aligning the same again with the valve is also difficult and removing any dirt on the valve is most difficult. Excavating the cavity and doing the job over again is, for practical purposes, the only effective address of these problems. Doing the job right the first time is, as usual, the idea. But work of this kind is not typically done by labor performed for pay on an hourly basis and there is hence little incentive to do it over if improperly performed the first time.
More pertinently, perhaps, if the work was done on an hourly basis there would be incentive to create problems that would require additional time to rectify. Most pertinently, however, it is noted that any problems with being able to easily access the shut valve in a curb box are literally buried when installation is completed and will not ‘come to light’ until the water or other fluid through the line is to be shut off. This work, moreover, is not done by the same people who installed the buried line and the valve in the curb box or other casing. Therefore there is little incentive indeed for ensuring that the job is done correctly in the first place. And if the valve is not operable when the time comes because access to the same through the curb box or other casing is not feasible because the valve is covered with dirt or the casing is misaligned the only solution is excavation. Only this time it wasn't expected and a backhoe must be brought in or the excavation manually performed. This is, in a word, expensive.
Discussion of the Prior Art
U.S. Pat. No. 44,904 for a ‘Water Plug Case’, issued Nov. 1, 1864 to J. G. Weldon provides an illustration of a curb box for a valve on a buried fluid line and further attests to the age of such structures which are still typically cast iron.
U.S. Pat. No. 173,972 issued Feb. 22, 1876 to J. Lancaster for a ‘Stop-Cock Boxing’ discloses a curb box with opposed arches and telescoping structure for accommodation of various depths. A cup at the top of the boxing is also disclosed “to receive whatever contents may enter same” and prevent “accumulation (that would) make it difficult to control the stop-cock”.
U.S. Pat. No. 4,030,519 issued Jun. 21, 1977 to Frank R. Zinn discloses a “valve cover for covering a buried valve and permitting access thereto with a two piece, rigid plastic housing having a square cross section which resists rotation in the ground.” At the lower end opposed openings are provided “in the housing walls through which the pipes extend from the valve” having “a plurality of fingers . . . to form a tapering passage which will accommodate different sizes of pipes”. (Abstract).
U.S. Pat. No. 4,691,733 issued Sep. 8, 1987 to Frank R. Zinn discloses a: “valve cover assembly and support member having opposed slots extending downwardly from the upper end thereof and extending into the lower end of a conventional valve cover to lock the valve against rotation and hold the valve in an upright position.” (Abstract) This cover is essentially inverted with respect to the arches of a conventional curb box as clearly depicted therein.
U.S. Pat. No. 6,354,325 issued Mar. 12, 2002 to Warnes et al. discloses an ‘Underground Access Conduit’ “for enclosing an underground area surrounding the actuating mechanism of a flow control valve” having a cup shaped body open at bottom and top with a horizontal plate fitted to the bottom opening with a plurality of resilient fingers upwardly deformed in contact with the valve for seating upon the same. The upper opening of the body is dimensioned to receive the lower end of a length of conventional polyvinylchloride (PVC) conduit in replacement of a curb box.
While the ‘Underground Access Conduit’ of Warnes et al. theoretically prevents the covering of an underground fluid line valve with earth when filling the cavity excavated for installation of this portion of the line and further eliminates any problems with alignment of the valve with a casing extending upwardly from about the valve by replacing the casing with a length of conduit engaging a housing seated upon the top of the valve, as a practical matter the structure is problematic because the exterior of the valve body concerned, as clearly shown therein, is tapered and the resilience of the fingers act to push the same upward. The assembly must hence be held downward with the top end of the conduit when filling the excavated cavity. This not only requires someone for holding the assembly down while someone else fills the cavity but effectively prevents use of a backhoe for the job as the same could easily inflict severe damage to the person holding the conduit. These drawbacks effectively render the approach suitable to amateurs only but state regulations require this work be done by a state licensed contractor. Apart from these failings it is further considered that only the dirt above the body is holding the same in place upon the valve as the PVC conduit is lightweight and hence further extremely susceptible to accidental displacement by a landscaper or anyone operating a machine in proximity to the top of the conduit including a riding lawnmower if the top of the conduit is or becomes exposed.
The valve covers disclosed by Zinn are intended to accommodate differing pipe diameters and to prevent rotation of a buried valve. No provision is made to prevent the covering of the valve with dirt or angular misalignment of the valve with the casing if tipped or otherwise disturbed by a backhoe during filling of the excavated cavity. Similarly, the ‘stop-cock boxing’ disclosed by Lancaster is intended to prevent debris or earth from entering the box or case but if the same is disturbed during filling of the excavated cavity there is nothing to stop earth from entering the arches at the bottom and covering the valve and there is no provision for ensuring that the valve is maintained in an upright disposition.
Statement of Need
Refilling an excavated cavity for an underground fluid line including a valve upon the same is commonly performed with a backhoe, i.e. a powered machine. A casing, or curb box in the case of a typical water shut off valve on a water line to a residential structure, is typically used to preserve access to the valve so the same can be operated at a later time without re-excavating a cavity. During filling of the cavity this casing, typically a curb box, is often disturbed by the backhoe causing two problems: entrance of earth from the bottom of the casing sufficient to cover the valve and misalignment of the valve with the casing or casing with the valve. Either condition easily prevents operation of the valve through the casing with the long handle wrench used for this and necessitates re-excavation. The known prior art fails to effectively address these problems and hence a need is considered to exist for a means of ensuring that operable access to an underground fluid valve through a casing is maintained even if the casing is disturbed while filling the cavity excavated for installation of the buried line and valve thereto.